KR20150055266A - Sheet Casting Biodegradable resin composition including polylactic acid - Google Patents

Abstract

The present invention relates to a biodegradable resin composition having an eco-friendly property and a sheet molded from the composition. In the present invention, provided are a biodegradable resin composition, which comprises a mixture of poly lactic acid with high hardness, good impact resistance and moldabiltiy and poly butyleneadipate-co-terephthalate with high flexibility as a main ingredient and added inorganic fillers, thereby leading to good tensile strength and elongation, and a sheet molded from the biodegradable resin composition.

Description

[0001] The present invention relates to a sheet-forming biodegradable resin composition comprising polylactic acid,

TECHNICAL FIELD The present invention relates to a biodegradable resin composition, and more particularly, to a biodegradable resin composition which is environmentally friendly and excellent in impact resistance and moldability, and a sheet molded from the composition.

Plastic is light, easy to process, mass-producible, and has excellent durability and mechanical properties, making it an important material in real life. However, as the problem of environmental pollution caused by the decomposition and disposal process of waste plastics in the world is emerging as a social problem, biodegradable resins in domestic and overseas industries are actively developed for various applications such as packaging containers and electronic product cases And has been attracting attention as an eco-friendly resin.

In order to put the packaging container using the biodegradable resin into practical use, it is required to have high hardness in order to maintain the shape after molding, and it should not be damaged by an external impact during use. Among the commercially available biodegradable resins, the most commonly used ones can be roughly classified into those obtained by synthesis and those obtained by fermenting natural products and polymerizing them. However, the aliphatic polyester-based biodegradable resin produced by the synthesis is not only expensive, but also has a lower hardness and higher flexibility than conventional plastic products, and thus is used only in the form of envelopes rather than packaging containers. . The polylactic acid obtained by fermenting starch has better transparency than other biodegradable resins and has a relatively high tensile strength and hardness. However, the polylactic acid resin has good mechanical strength, but the elongation is within 10% It is very low and breakage due to the impact is easily caused. Therefore, after the vacuum molding at a depth of 3 cm or more, the thinned portion may be easily broken and holes are formed in the vacuum molding process. In addition, due to the thermal properties of the material, the thermal deformation temperature is low and the shape stability is poor due to the slow cooling rate.

In order to solve these problems, methods for securing brittleness by using biaxial stretching process in the process of softening polylactic acid or forming a sheet are required. For example, Korean Patent Laid-Open Publication No. 10-2004-0061885 discloses a biodegradable resin composition prepared by mixing a starch mixture prepared by adding a crosslinking agent and a plasticizer to starch, and a biodegradable resin such as polylactic acid . In the case of softening, it is possible to use a plasticizer or the like. However, during the sheet molding and the vacuum molding, fine fume is generated frequently, and the shear thinning phenomenon of the flow becomes severe during the vacuum molding process, There is a problem such as thinning.

KR 2004-0061885

An object of the present invention is to provide a biodegradable composition containing polylactic acid and having environmental friendliness and excellent impact resistance and moldability and a molded product thereof.

In order to achieve the above object, the present invention provides a biodegradable resin composition containing polylactic acid and polybutadene adipate-co-terephthalate.

In the present invention, the polylactic acid may be a mixture of a crystalline polylactic acid and an amorphous polylactic acid.

In the present invention, the polylactic acid may be 60 to 90% by weight of the crystalline polylactic acid and 10 to 40% by weight of the amorphous polylactic acid.

The present invention also relates to a composition comprising a mixture of polylactic acid and polybutadienadipate-co-terephthalate in an amount of from 50 to 85% by weight of polylactic acid and from 15 to 50% by weight of polybutene adipate-co-terephthalate good.

 The biodegradable resin composition of the present invention may further comprise at least one additive selected from the group consisting of a viscosity modifier, an inorganic filler, and a processing additive to the mixture of polylactic acid and polybutylene adipate-co-terephthalate.

 The inorganic filler may be at least one selected from the group consisting of calcium carbonate, talc, magnesium carbonate, scorching, clay, nitrate, silica and aluminum. And the processing additive may be selected from the group consisting of antioxidants, amide-based lubricants and pigments.

The present invention also provides a sheet molded from the biodegradable resin composition.

The polylactic acid-containing biodegradable resin composition according to the present invention is excellent in elongation (%) and tensile strength (kgf / cm ² ) as a main component of polylactic acid having high hardness and excellent impact resistance, It is advantageous to overcome the problem caused by low physical properties.

In addition, the composition of the present invention can prevent deformation of the product due to recrystallization or the like caused by low melt strength by mixing amorphous polylactic acid with crystalline polylactic acid with low moldability due to existing high hardness.

The composition of the present invention can improve flexibility by mixing polybutadelene adipate-co-terephthalate to improve the limitations that occur during molding or cutting due to the hardness of polylactic acid. Further, the composition of the present invention can freely control the melt flowability of the biodegradable resin composition by employing a viscosity controlling agent.

Further, the present invention is useful as a material of an environmentally friendly molded product (sheet, packaging material or packaging container) containing a biodegradable resin composition.

Fig. 1 (a) shows a molded article obtained by the method of Example 1 using the biodegradable resin composition of the present invention. Fig.
Fig. 1 (b) shows a molded article obtained by the method of Example 2 using the biodegradable resin composition of the present invention.
Fig. 1 (c) shows a molded article obtained by the method of Example 3 using the biodegradable resin composition of the present invention.
Fig. 1 (d) shows a molded article obtained by the method of Example 4 using the biodegradable resin composition of the present invention.
1- (e) shows a molded article obtained by the method of Comparative Example 1 using the biodegradable resin composition of the present invention.

The biodegradable composition for sheet molding comprising the polylactic acid of the present invention will be described in detail as follows.

The present invention is a biodegradable resin composition for sheet molding comprising polylactic acid and polybutadene adipate-co-terephthalate.

The polylactic acid used in the present invention is advantageous in heat resistance and excellent strength among the biodegradable resins, and has excellent transparency after molding, and is used for food packaging containers, films, coatings, and medical materials. The polylactic acid used in the present invention may have a number average molecular weight (Mw) of 50,000 to 150,000. Also, polylactic acid is produced by polymerization from monomers derived from D-lactide and L-lactide, and therefore, D-lactide and L-lactide ) Can be freely controlled, and the content of each component can be adjusted according to the application. In order to achieve the object of the present invention, it is preferable to use a crystalline polylactic acid having a D-lactide content of 1 to 5 wt% and an amorphous polylactic acid having a D-Lactide content of 9 wt% It is preferable to use them in combination.

The polylactic acid used in the composition of the present invention is one in which the crystalline polylactic acid is 60 to 90% by weight and the amorphous polylactic acid is 10 to 40% by weight. This exhibits impact resistance and heat resistance possessed by crystalline polylactic acid, and flexibility is imparted by amorphous polylactic acid, so that mutual characteristics are mutually complemented and physical properties are improved. Particularly, the shape change of the molded article can be minimized by using the mixing ratio of the present invention.

 The biodegradable resin composition of the present invention is more preferably one containing polybutylene adipate-co-terephthalate. This is for softening the polylactic acid. When the polylactic acid is used singly, the polylactic acid has a hardness of the polylactic acid, so that the polylactic acid has a low cooling rate and a high flexibility of polybutene Adipate-co-terephthalate may be mixed to improve the flexibility of the biodegradable resin. The number-average molecular weight (Mn) of the polybutadene adipate-co-terephthalate used in the present invention may be 20,000 to 100,000.

The mixture of polylactic acid and polybutadene adipate-co-terephthalate may be used in the range of 50 to 85% by weight of polylactic acid and 15 to 50% by weight of polybutadene adipate-co-terephthalate. By using the composition of the present invention, the vulnerability is further improved, the long-term storage property is improved, the deformation due to the load is improved, and it is more economical.

In another embodiment of the present invention, the biodegradable resin composition may further comprise a viscosity adjusting agent in a mixture of polylactic acid and polybutadien adipate-co-terephthalate.

The viscosity modifier may be a mixture of polylactic acid and polybutadienadipate-co-terephthalate, and a mixture of polylactic acid and polybutadiene adipate-co-terephthalate, . Preferably, it is at least one selected from peroxide, diisocyanate, and cross-linking agent, but is not limited thereto.

The peroxide is selected from the group consisting of dibenzoyl peroxide, 2,5-dimethyl-2,5 di (t-butylperoxy) -hexane, di- (2-t-butylperoxyisopropyl) benzene, and the like.

The diisocyanate is preferably, but not limited to, diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), or isophorone diisocyanate (IPDI).

The crosslinking agent may be selected from the group consisting of trially isocyanate (TAIC) box (2,2'-bis (2-oxazoline)), Butyl acrylate-methylmethacrylate grafted co-polymer, butyl acrylate rubber-styrene copolymer, and the like. A styrene acrylate copolymer, a modified uretonimine, a polycarbodiimide, a bis- (2,6-diisopropylphenyl) carbodiimide (Bis- (2,6-diisopropylphenyl) carbodimide) or a monomeric carbodiimide, or a mixture thereof.

 The content of the viscosity adjusting agent is preferably 0.01 to 3.0 parts by weight, based on 100 parts by weight of the mixture of polylactic acid and polybutadien adipate-co-tertalate. And more preferably 0.7 to 1.3 parts by weight. By using the content of the viscosity controlling agent according to the present invention, the melt flow index can be adjusted so that the composition is tested in a range of 5 to 15 g per 10 minutes when the melt flow index of the biodegradable resin composition is tested at 200 캜 under a load of 5 KG. When the flowability exceeds 15 g, the thickness becomes too thin at the wall surface after molding, the structure becomes weak, the molding is not performed while the pore is generated, and when the flowability is less than 5 g, the sheet formability is decreased, The material may be deteriorated due to an excessive rise of the material.

In another embodiment of the present invention, the biodegradable resin composition of the present invention includes a mixture of polylactic acid and polybutadienadipate-co-terephthalate further containing an inorganic filler and a processing additive. The inorganic filler not only secures the economical efficiency of the product but also acts as a crystallization nucleus agent, thereby increasing the degree of crystallization and improving rigidity, transparency and gloss. Further, it is possible to improve the physical properties of the product by improving the cooling rate of the polylactic acid after the vacuum molding by acting as a nucleophilic agent.

The inorganic filler may be at least one selected from calcium carbonate, talc, magnesium carbonate, alumina, clay, carbonaceous material, silica and aluminum, but is not limited thereto and any inorganic filler generally used in this field is not limited . Specifically, calcium carbonate and talc are most preferable.

The content of the inorganic filler is not particularly limited, but may be 5 to 20 parts by weight of the inorganic filler per 100 parts by weight of the mixture of polylactic acid and polybutadien adipate-co-terephthalate. Although the use of the filler is economical, excessive use leads to an increase in the specific gravity, and since the workability of the biodegradable resin composition is lowered, it is preferable that the amount of the filler is 5 to 20 parts by weight per 100 parts by weight of the mixture of polylactic acid and polybutadiene adipate- But it can be adjusted within the range of attaining the object of the present invention. The particle size of the inorganic filler is not particularly limited, but may be in the range of 1 to 10 m on average, and more preferably 2 to 8 m, but is not limited thereto.

The processing additive is preferably at least one selected from an antioxidant, an amide-based lubricant and a pigment. The antioxidant may include a primary antioxidant and a secondary antioxidant. The primary antioxidant functions as a radical scavenger to stabilize the plastic by reacting with the radicals generated in the plastic. Representative substances include phenol and aromatic amine. The two groups of substances release hydrogen to stabilize the radicals, which themselves change into radicals, which remain in a stable form through resonance effects or rearrangement of electrons. The secondary antioxidants function as releasing peroxide, and phosphite compounds and sulfur compounds can be used. The secondary antioxidant plays a role of a primary antioxidant and can be used as a stabilizer having good heat resistance and processability and excellent antifouling effect. As the first oxidizing agent used in the present invention, (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane ((3,5- (2,4-di-t-butylphenyl) phosphite, but is not limited thereto. The content of the antioxidant may be, for example, May be used in an amount of 0.1 to 0.3 parts by weight of the primary antioxidant and 0.1 to 0.3 part by weight of the secondary antioxidant, based on 100 parts by weight of the mixture of polylactic acid and polybutadien adipate-co-teratolate.

The amide type lubricant serves to lubricate the surface of the metal in contact with the resin during processing, molding and extrusion, thereby retarding the melting of the resin. The amide type lubricant serves as an additive for improving the slipability of the mold surface or extruder, The melt viscosity of the resin is lowered and the processing temperature is lowered and the processing time is shortened so that the deterioration during processing is reduced and the quality of the product can be improved. The lubricant used in the present invention is preferably an amide wax (Erucyl amide), but is not limited thereto.

 The content of the amide-based lubricant may be 1 to 5 parts by weight based on 100 parts by weight of the mixture of polylactic acid and polybutadien adipate-co-tertalate.

Pigments are dyes that do not dissolve in water, oil or alcohol. They are mixed with resin to prevent rusting and increase the strength of gloss and film. The pigment used in the present invention is preferably titanium dioxide (TiO ₂ ), but is not limited thereto.

The content of titanium dioxide (TiO ₂ ) may be 1 to 3 parts by weight based on 100 parts by weight of a mixture of polylactic acid and polybutadien adipate-co-tertalate.

Can be prepared by mixing and extruding a biodegradable resin composition composed of the composition of the present invention. As the extruder, a conventional extruder can be used. For example, the extruder can be extruded using a twin extruder, but not limited thereto. The formation of the biodegradable resin composition obtained by extrusion may be in the form of a pellet. After extrusion, the obtained biodegradable resin composition can be vacuum molded by using a sheet produced by sheet molding using a sheet molding machine to produce a packaging container.

 The sheet forming machine can be extruded through a conventional method, for example, a die through an extruder, and cooled using a roller to obtain a sheet-like product.

Vacuum molding is performed by using a sheet produced through sheet molding, and when the heating state of the sheet is a sagging phenomenon for vacuum molding using a top heating type vacuum molding machine, a product is molded by vacuuming from the bottom, After cooling, the product is discharged by compressed air. Molds with multiple holes may be used to enhance productivity, but are not limited to these.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. These embodiments are provided for illustrative purposes only and are not intended to limit the present invention.

Example 1

5.3 kg of crystalline polylactic acid (crystalline polylactic acid having a D-lactide content of 1.5 wt%), 2.9 kg of an amorphous polylactic acid (crystalline polylactic acid having a D-lactide content of 12.5 wt%) and polybutylene adipate- (MDI) (0.01 kg) and di- (2-t-butylperoxyisopropyl) benzene were mixed with 1.8 kg of phthalate (crystalline polylactic acid having a terephthalate content of 50 wt%) to prepare a raw material composition. 1 kg of calcium carbonate (average particle size: 1 탆), talc (average particle diameter: 5.5 탆), 0.5 kg of triaryl isocyanurate (TAIC), 0.012 kg of di- (2-t- butylperoxyisopropyl) (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane) as a processing additive, a first antioxidant (3,5-di- (2,4-di-t-butylphenyl) phosphite) and 0.02 kg of a second antioxidant tris (2,4-di- Wax (Erucyl amide) were mixed by the addition of TiO ₂ (average particle diameter 0.16㎛) 0.118kg to 0.2kg, pigments. The mixture was extruded using a co-axial twin-screw extruder having a diameter of 32 mm and an L / D of 40. Compound extrusion was performed at a screw rotation speed of 200 rpm at a raw material feed rate of 25 kg / hr and an extrusion temperature was set at an average of 170 캜. The shape of the biodegradable resin composition obtained by extrusion showed a pellet shape. The pellet-shaped biodegradable resin composition was used to produce a sheet with a sheet molding machine. The temperature condition of the sheet molding machine was adjusted to an average of 170 DEG C for the cylinder section, 160 DEG C for the mold section and 45 DEG C for the roll section. And then subjected to vacuum molding using a sheet produced through sheet molding to finally produce a molded article (Fig. 1- (a)). The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 2

4.8 kg of crystalline polylactic acid, 3 kg of amorphous polylactic acid, and 2.2 kg of polybutadene adipate-co-terephthalate were mixed to prepare a raw material composition. Di- (2-t-butylperoxyisopropyl) (Fig. 1- (b)) was prepared in the same manner as in Example 1, except that 0.008 kg of 2-t-butylperoxyisopropylbenzene and 0.07 kg of arylisocyanurate (TAIC) were added. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 3

5 kg of crystalline polylactic acid, 2.5 kg of amorphous polylactic acid and 2.5 kg of polybutylene adipate-co-terephthalate were mixed to prepare a raw material composition. As a viscosity modifier, 0.04 kg of diphenylmethane diisocyanate (MDI) Except that 0.003 kg of di- (2-t-butylperoxyisopropyl) benzene and 0.05 kg of triarylisocyanurate (TAIC) were added in the same manner as in Example 1 (Fig. 1- (c)). The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 4

5 kg of crystalline polylactic acid, 1.5 kg of amorphous polylactic acid and 3.5 kg of polybutadene adipate-co-terephthalate were mixed to prepare a raw material composition. As a viscosity modifier, 0.06 kg of diphenylmethane diisocyanate (MDI) 0.01 kg of di- (2-t-butylperoxyisopropyl) benzene, 0.8 kg of calcium carbonate (average particle diameter 1 탆) and 0.8 kg of talc (average particle diameter 2 탆) (Fig. 1- (d)). The results are shown in Table 1 below. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 5

, 0.08 kg of diphenylmethane diisocyanate (MDI), 0.07 kg of di- ((meth) acrylic acid) diisocyanate (MDI) as a viscosity modifier, and 4.8 kg of crystalline polylactic acid, 2.2 kg of amorphous polylactic acid and 3 kg of polybutylene adipate- Except that 0.009 kg of di- (2-t-butylperoxyisopropyl) benzene and 0.05 kg of triarylisocyanurate (TAIC) were added in the same manner as in Example 1 To prepare a molded article. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 6

A raw material composition was prepared by mixing 3.9 kg of crystalline polylactic acid, 2.1 kg of amorphous polylactic acid, and 4 kg of polybutylene adipate-co-terephthalate. As a viscosity modifier, 0.07 kg of diphenylmethane diisocyanate (MDI) 0.012 kg of di- (2-t-butylperoxyisopropyl) benzene and 0.05 kg of triarylisocyanurate (TAIC) and 1 kg of calcium carbonate (average particle size of 1 μm) as an inorganic filler And 0.8 kg of talc (average particle size of 2 탆) were added to the mixture. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 7

6 kg of crystalline polylactic acid, 3 kg of amorphous polylactic acid and 1 kg of polybutylene adipate-co-terephthalate were mixed to prepare a raw material composition. As inorganic filler, 1 kg of calcium carbonate (average particle diameter 1 μm) and talc (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane (3,5-di-t-butyl-4-hydroxyhydrocinnamate) as a processing additive, ) And 0.02 kg of a second antioxidant tris (2,4-di-t-butylphenyl) phosphite), 0.02 kg of an amide wax (Erucyl amide) and 0.118 kg of TiO ₂ (average particle diameter: 0.16 탆) as a pigment were added to the mixture. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 8

6 kg of crystalline polylactic acid, 3 kg of amorphous polylactic acid and 1 kg of polybutadene adipate-co-terephthalate were mixed to prepare a raw material composition. As a viscosity controlling agent, 0.03 kg of diphenylmethane diisocyanate (MDI) (TAIC) was added to the extruded product to obtain a molded article. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Example 9

2 kg of crystalline polylactic acid, 4.5 kg of amorphous polylactic acid, and 3.5 kg of polybutylene adipate-co-terephthalate were mixed to prepare a raw material composition. As a viscosity modifier, 0.03 kg of diphenylmethane diisocyanate (MDI) Except that 0.01 kg of di- (2-t-butylperoxyisopropyl) benzene was added as a polymerization initiator. The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

Comparative Example 1

6.5 kg of crystalline polylactic acid and 3.5 kg of amorphous polylactic acid were prepared from the raw material composition, 0.03 kg of diphenylmethane diisocyanate (MDI) and 0.04 kg of triarylisocyanurate (TAIC) as an inorganic filler, (3,5-di-t-butyl-4-hydrocyclinnamate) methane (((1, 3-di-tert- (2,4-di-t-butyl-4-hydroxyhydrocinnamate) methane), 0.02 kg of a second antioxidant tris (2,4- t-butylphenyl) phosphite), 0.2 kg of amide wax (Erucyl amide) and 0.118 kg of TiO ₂ (average particle diameter 0.16 μm) as a pigment were added and mixed. The mixture was extruded using a twin-screw twin-screw extruder having a diameter of 32 mm. The properties of the biodegradable resin composition obtained by extrusion showed a pellet shape. The obtained biodegradable resin composition was used to produce a sheet with a sheet molding machine. The temperature condition of the sheet molding machine was adjusted to an average cylinder temperature of 170 DEG C, an average mold temperature of 160 DEG C, and an average roll temperature of 45 DEG C. And subjected to vacuum molding using a sheet produced through sheet molding to finally produce a molded article (Fig. 1- (e)). The pellet-shaped biodegradable resin composition obtained by extrusion was used to prepare a standard specimen according to each physical property evaluation method, and physical properties were measured. The results are shown in Table 1 below.

The physical properties of the molded product obtained through Examples and Comparative Examples were measured according to ASTM D412, and the MI was measured according to ASTM D2240 according to Hardness D (press) and ASTM D1238.

As can be seen from Table 1, the biodegradable resin composition according to the present invention contains polylactic acid and polybutene adipate-co-terryphthalate, so that compared with the case of not using polybutene adipate-co- (Comparative Example 1). As shown in Examples 1 to 9, it can be seen that the tensile strength is 259 to 510 kgf / cm < 2 > and the elongation percentage is 6 to 360%.

The biodegradable resin composition according to the present invention is characterized in that the polylactic acid contains 60 to 90% by weight of the crystalline polylactic acid and 10 to 40% by weight of the amorphous polylactic acid, so that the weight percentage of the amorphous polylactic acid deviating from the composition of the present invention is 40% (Example 9), softening of the polylactic acid occurred, but due to the excessive content of the amorphous polylactic acid, the melt viscosity after melting was high, so that the product was deformed due to the lowered cooling temperature in the process of cooling the product after molding Resulting in poor moldability. However, when polylactic acid containing 60 to 90% by weight of crystalline polylactic acid and 10 to 40% by weight of amorphous polylactic acid was used (Examples 1 to 8), hardness D 70 to 80 D, melt flow index 5.2 to 25 g / (The hardness, the melt flow index, the tensile strength, and the elongation) with a tensile strength of 200 to 5 kg, a tensile strength of 256 to 502 kgf / cm ² and an elongation of 6 to 356%.

Also included according to the present invention are polylactic acid and polybutene adipate-co-terephthalate, but also include polylactic acid in an amount of from 50 to 85% by weight and polybutene adipate-co-terephthalate in 15 to 50% (Examples 7 and 8) contained 50 to 85% by weight of polylactic acid conforming to the composition range of the present invention, polylactic acid having 50 to 85% by weight of polylactic acid, The results of Examples 1 to 6 containing 15 to 50% by weight of butene adipate-co-terephthalate exhibited remarkably excellent mechanical properties (hardness, melt flow rate) of 259 to 455 kgf / cm ² and elongation percentage of 136 to 356% Index, tensile strength, elongation).

More preferably 50 to 85% by weight of polylactic acid according to the composition of the present invention, 15 to 50% by weight of polybutadene adipate-co-terephthalate, 60 to 90% by weight of crystalline polylactic acid, (200 ° C * 5 kg) and a tensile strength of 259 to 455 kgf / cm 2 (Examples 1 to 6) in the case of using polylactic acid containing polylactic acid ² , and an elongation percentage of 136 to 356%, respectively, which are excellent in mechanical properties (hardness, melt flow index, tensile strength, elongation).

From Table 1, it can be seen that the biodegradable resin composition according to the present invention contains a viscosity control agent in a mixture of polylactic acid and polybutadienadipate-co-terephthalate, as compared with the case of not using a viscosity control agent (Example 7 ) And a melt flow index of 5.2 to 10.2 g / 10 min (200 ° C * 5 kg) as in the results of Examples 1 to 6 and 8 to 9.

Claims (11)

A biodegradable resin composition comprising polylactic acid and polybutylene adipate-co-terephthalate.
The method according to claim 1,
Wherein the polylactic acid contains 60 to 90% by weight of crystalline polylactic acid and 10 to 40% by weight of amorphous polylactic acid.
The method according to claim 1,
The mixture of polylactic acid and polybutadene adipate-co-
50 to 85% by weight of polylactic acid and 15 to 50% by weight of polybutylene adipate-co-terephthalate.
The method according to claim 1,
With respect to the biodegradable resin composition,
A viscosity modifier, an inorganic filler, and a processing additive.
5. The method of claim 4,
Wherein the viscosity modifier is at least one selected from the group consisting of peroxide, diisocyanate and crosslinking agent.
5. The method of claim 4,
And 0.1 to 2.0 parts by weight of a viscosity modifier based on 100 parts by weight of the mixture of polylactic acid and polybutadien adipate-co-terephthalate.
5. The method of claim 4,
Wherein the inorganic filler is at least one selected from calcium carbonate, talc, magnesium carbonate, dazzle, clay, nitrate, silica and aluminum.
5. The method of claim 4,
And 5 to 20 parts by weight of an inorganic filler based on 100 parts by weight of the mixture of the polylactic acid and the polybutylene adipate-co-terephthalate.
5. The method of claim 4,
Wherein the processing additive comprises one or two or more components selected from antioxidants, amide-based lubricants and pigments.
5. The method of claim 4,
A biodegradable resin composition comprising 0.2 to 0.5 parts by weight of an antioxidant, 1 to 5 parts by weight of an amide-based lubricant and 1 to 3 parts by weight of a pigment, based on 100 parts by weight of the mixture of polylactic acid and polybutylene adipate-co-terephthalate Composition.
A packaging container manufactured by sheet molding using the biodegradable resin composition according to claim 1.

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